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Finding the Fourth Proportional to 1,137.25, 1,569.28 and 639.79

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Solution

The fourth proportional to 1,137.25, 1,569.28 and 639.79 is: 882.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,137.25 : 1,569.28 = 639.79 : x
  2. Step 2: Convert to fraction form
    1,137.25/1,569.28 = 639.79/x
  3. Step 3: Cross multiply
    1,137.25x = 1,569.28 × 639.79
  4. Step 4: Simplify right side
    1,137.25x = 1,004,009.65
  5. Step 5: Solve for x
    x = 1,004,009.65/1,137.25
  6. Step 6: Final answer
    x = 882.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.